Effect of Tillage System, Intercropping and Nitrogen Fertilization on Growth, Yield of Corn (Zea mays L.) and Cowpea (Vigna sinensis) in a Gypsiferous Soil

Abstract

A field experiment was carried out during the agricultural season 2016 to study influence of tillage systems, intercropping and rate of nitrogen fertilization on growth and yield of corn and cowpea in a gypsiferous soil. The experiment was executed according to split-split plot design in three replicates. The study was consisted of two tillage systems, the reduced tillage (RT) and the conventional tillage (CT), and three levels of nitrogen 0, 60 and 120 Kg ha-1 (N0, N1, N2), respectively and four systems of intercropping viz: corn alone, cowpea alone, one line corn: one line cowpea and one line corn: two line cowpea, (A1,A2,A3,A4), respectively. Results showed the significant superiority of reduced tillage on conventional tillage in some growth and yield characteristics and N concentration for corn and cowpea. The highest corn grain yield was 6348 Kg ha-1 and the cozwpea green pods yield was 5040 Kg ha-1 for the reduced tillage compared with conventional tillage. Nitrogen fertilizer increased growth and yield characteristics of both crops where the level (120 Kg ha-1) gave the highest level of corn grain yield which was 7366 Kg ha-1, while it was 5372 Kg ha-1 for cowpea green pods yield. Intercropping caused an increase in most characteristics of growth and yield and nitrogen concentration in grains, where the grain yield in the crop system (one line corn - two line cowpea) gave 6864 Kg ha-1 of corn grain yield. Intercropping caused a reduction in most of the values of the growth and yield characteristics for cowpea while the system (cowpea alone) gave 6723 Kg ha-1 of. The triple interaction treatment between reduced tillage, N2 (120 kg N ha-1) and the system (one line corn: two line cowpea) was superior in some growth characteristics and corn grain yield (8904 kg ha-1), while the triple interaction between reduced tillage, N1 (60 kg N ha-1) and cowpea alone was superior in chlorophyll, dry weight yield, fresh seeds and pods yield and gave 7702 kg ha-1 of cowpea green pods yield.